Credit card sized memory cards are commercially available, such as MF3129-M7DAC01 from Mitsubishi Electric Corporation. This particular card contains 128 KB of static random access memory (SRAM) powered by a contained battery. The card container has dimensions of about 85.times.54.times.about 3.4 millimeters, has an electrical connector at one end and a cavity at the other end for receiving and holding the battery. It also has a slide switch at the other end operated to turn a write protect feature on and off.
The referenced memory card is constructed by mounting the individual semiconductor memory and related devices on a thin printed circuit board and attaching a connector to the board. A plastic molded frame having a marginal and transverse skeleton and internal openings mates with the printed circuit board and connector combination. Top and bottom panels of such as sheet metal then mount over the openings through the frame to enclose the printed circuit board and semiconductor devices. Later, the battery can be inserted in its opening and be secured in place with a plastic holder and screw. Adhesive sheets, one each on the top and bottom, secure the panels in place.
Memory cards find utility in numerous electronic systems. In personal computers they supplement or replace floppy disks by carrying software programs and data and are connected to the internal logic through a port on such as the side of the computer cabinet. Portable personal computers, notebook computers, and pocket diaries particularly find memory cards convenient because they avoid the need for the expense, power requirements, bulk, and weight of a disk drive; the memory card needs only an electrical connector and minimal structural support.
Facsimile and copy machines can use a memory card to store data related to usage control. Typewriters and printers can use a memory card to store desired memory fonts. Word processors can use a memory card to store text. Hand-held terminals can use memory cards to store inventory control information. Electronic cash registers can use memory cards to store price information. Controllable machinery can use memory cards to store automation control information. Programmable controllers can use memory cards to store process control data. Electronic game systems can use memory cards to store the specifics of games to be enacted on TV screens by the players.
Other areas that can benefit from the use of memory cards include bulk data acquisition such as in music and photography, where the desired song or picture is stored in the memory devices of the card.